Line 1 Summary

Get out the microscope, because we’re going through this poem line-by-line.

Line 1

Now we must praise heaven-kingdom's Guardian,

Speaking in the first-person plural (technical term for "we"), the speaker in
the hymn declares that it's time to get our praising on.

God is the subject of this poetic awe and admiration, but he doesn't appear as just "God." Heck no. This line gets the metaphors
going with "heaven-kingdom's Guardian." "Heaven-kingdom" is an example
of a specific form of Anglo-Saxon compound word called a kenning (see more under "Imagery."). Keep your eyes open for more examples.

And while you're at it: Mind the Gap! That cavernous space dividing the line in half is called a caesura, or pause, and it helps to organize each line's orderly system of stresses and alliteration (for more, see "Form and Meter").